I think the key thing is that if you have two cones facing each other, both moving in and out identically, if the behaviour of the cone of one of the drivers, from one end of its excursion to the other end of its excursion, is not linear, both cones will have that behaviour and double the effect of the non-linearity.
Whereas if the second driver is mechanically reversed and its magnet and basket is now facing the cone of the first driver, as the 'normal' cone exhibits the non-linearity at a given point in its excursion, the 'reverse' cone's non-linearity will be doing the exact opposite of the 'normal' cone, meaning the non-linearity will cancel out.
Does that make any sense? I am struggling to explain it todaylol
Sorry, I started writing something and then changed my mind, but forgot to take it out before I pressed Submit Reply and walked away, and now I can't edit it...
lolThe above is what I was intending to write!
"It would be very interesting to see some Klippel data on this arrangement"
A Dumax on a PP pair of 8's showed about a 3dB increase in maximum output vs normal mounting. Small differences in assembly affecting coil height in the gap tend to cancel out in PP, assuming these differences are all in the same dirrection, all too high, or all too low (in the gap).
A Dumax on a PP pair of 8's showed about a 3dB increase in maximum output vs normal mounting. Small differences in assembly affecting coil height in the gap tend to cancel out in PP, assuming these differences are all in the same dirrection, all too high, or all too low (in the gap).
Hi chrapladm,
In post#2 from tb46 you can find the info about the PPSL simulation.
Cheers,
Djim
If you do build one, make sure to post up your thoughts on it!
I only have limited experience so my opinion probably doesn't really count, but I love the way mine 'disappear' and are somehow heavyweight when needed but 'thin'/'airy' the rest of the time - it's really hard to explain
lolFWIW, every Sealed, non-PPSL alignment I've heard since (admittedly not a lot, but still...) has sounded 'fat' and really obviously 'there' when listening. My PPSL lets me really listen to the music and completely forget about the system!
That's probably not very clear at all
lol, but if you have experience with all the other various algnments, I am very interested in hearing your opinion so you should build it lolIt would be great to get another convert to the PPSL cause!
Well I can build the Othorn but will have to get another pair of 21's to do the PPSL. Although it would be more cost effective for me to do an 18" PPSL vs Othorn. Then maybe a PPSL vs my Hybrid.
Are there any 18's that can do a low tune such as 25hz from BC, 18 SOund or Beyma?
I think I have simulated everything from BC and Beyma but maybe I missed something. The best woofer I liked was the 18PS100. BUT that was only 29hz. The best option for a flat FR 18" that I could find for a low tune was the 2245H from JBL. I might try and get a pair of 2240's and recone them later. Or just find something from the above manufacturers that works.
AND the 18SW115 is out of my price range. 500 for that one and TBW100 is about 360. So this wont happen overnight but give me some months, maybe Xmas, and I should have some built.
I think I will just stick with the 18PS100. I planned on using these in a 3 way design anyways. I was thinking of using maybe the TBW100 but I dont really need the extra excursion. I wish I knew the Xlim on the PS100 though. BUT the PS100 is about 120 dollars less per pair.
SO PPSL 28hz 18PS100 vs Othorn I can probably do. Not perfect but should be roughly the same tune at least.
Are there any 18's that can do a low tune such as 25hz from BC, 18 SOund or Beyma?
I think I have simulated everything from BC and Beyma but maybe I missed something. The best woofer I liked was the 18PS100. BUT that was only 29hz. The best option for a flat FR 18" that I could find for a low tune was the 2245H from JBL. I might try and get a pair of 2240's and recone them later. Or just find something from the above manufacturers that works.
AND the 18SW115 is out of my price range. 500 for that one and TBW100 is about 360. So this wont happen overnight but give me some months, maybe Xmas, and I should have some built.
I think I will just stick with the 18PS100. I planned on using these in a 3 way design anyways. I was thinking of using maybe the TBW100 but I dont really need the extra excursion. I wish I knew the Xlim on the PS100 though. BUT the PS100 is about 120 dollars less per pair.
SO PPSL 28hz 18PS100 vs Othorn I can probably do. Not perfect but should be roughly the same tune at least.
The usable band width of a ppsl is much greater than that of a TH,
wouldn't you think ?
Hi CRESCENDO,
Aren't you forgetting something?.... a Push-pull loaded TH
Cheers,
Djim
fwiw,my subjective opinion is that in my double 15th, speakers face to face sound "fuller"then 1speaker reversed aka ppsl.Hi Djim,
How could I forget? Absolutely, if someone has experience with a PPSL-TH, I'd love to hear their subjective opinions on that as well
Cheers!
probaply due to harmonics,so we left it that way.
Hi epa,
Perhaps the 'fuller' sound is the result of the 10 liter difference at S2 between Push-Pull and 'normal' configuration.
I have to admit we overlooked some of the difference in volume at the time of our blind test for the dual tham that I have mentioned in an old post.
Cheers,
Djim
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I built the sub DJK post #115 of this thread in January of this year using Eminence Kappa Pro-15LF-2 15 drivers.
This is the best bass I have had. I like it better than my IB subs I had in my pervious home.
Very detailed yet has realism, body and punch. You can feel it when feel it is in the recording, yet has tone and subtleties too.
I use it with an OB set up crossed at 70 hz with a 2nd order on a MiniDSP running the sub driving it with 250 watt chip amp
This is the best bass I have had. I like it better than my IB subs I had in my pervious home.
Very detailed yet has realism, body and punch. You can feel it when feel it is in the recording, yet has tone and subtleties too.
I use it with an OB set up crossed at 70 hz with a 2nd order on a MiniDSP running the sub driving it with 250 watt chip amp
Djim, You are right.
Fuller bass can be distortion.
I swapped out double 15 for 4 x 12" ppsl and some slam went away (crossing 24db@150hz).
Plenty of couch shaking, just less impactful slam.
I also have a buddy at work when his friends were doing car audio, they missed the seeming slam that went away when trying ppsl (same area box, amp, car, etc.).
I sometimes miss the fake bass......
Fuller bass can be distortion.
I swapped out double 15 for 4 x 12" ppsl and some slam went away (crossing 24db@150hz).
Plenty of couch shaking, just less impactful slam.
I also have a buddy at work when his friends were doing car audio, they missed the seeming slam that went away when trying ppsl (same area box, amp, car, etc.).
I sometimes miss the fake bass......
LOL.... I think some times the same.
I think it comes from when i attend live music ( whicch is a lot) the spl level is much higher and we feel it more. The plumped up sound gives us some of that feel maybe?
Could the impact transients be helped by better midbass?
I say this because I heard a system the other day that used a basic dual 18 ported cabinet and a 3way top with horned 12's. That was VERY tactile. And I mainly contribute the tactile slam to the mains. The subs were fine and did well but those mains were awesome.
SO hopefully I dont lose too much of what I like in a sub by trying PPSL design. Although I am a big fan of FLH design subs anyways.
Thats my opinion as of late. For me the slam I am liking was in the 300-600ish range. The bass can add some to it also but nothing like higher up.
Now I just need to see if I can get a PPSL design started.
I could use some 10's but they are not much of a subwoofer. More like bass driver. Beyma Either way
Now I just need to see if I can get a PPSL design started.
I could use some 10's but they are not much of a subwoofer. More like bass driver. Beyma Either way
Thats my opinion as of late. For me the slam I am liking was in the 300-600ish range. The bass can add some to it also but nothing like higher up.
Now I just need to see if I can get a PPSL design started.
I could use some 10's but they are not much of a subwoofer. More like bass driver. Beyma Either way
Pick up a couple of SI HT18 for $159 each before they disappear forever?
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I would then you towards my build thread
lol- Status
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